This is crucial to note because it disproves the idea that "Zumthor's architecture is preoccupied with materials and tectonics" so that "his design process somehow began and ended with concerns about physical matter" (Platt & Spier 2001, 21). If this were the case, the weight of the stone itself would likely have been highlighted, but instead, Zumthor chooses to subvert this weight by punctuating the stone with light, thus simultaneously imbuing the structure with the apparent timelessness of a stone mountain with the airy elevation of its position in the atmosphere. This effect helps to embody phenomenology's nuanced conception of materials and their relation to a structure's context, because the focus is not necessarily on the material itself, but rather its functional and emotional role within the space as a whole. Zumthor's use of stone is not a celebration of granite as such (in the way that the international style seems to be a celebration of steel and glass), but rather a celebration of the interplay between the specific granite of the mountain and the open sky above it. This careful attention to emergent emotional and perceptive experience produced by the interaction between a relatively few elements continues in the interior of the building, because the interior is composed of a "complex of interconnected open and closed geometric caves and caverns" which include the water of the baths in such a way as to give the impression of an interior etched over the course of millions of years but paradoxically intended for human use (Henry & Taylor 2005, 47). The baths utilize "the warm, therapeutic spring waters that rise out of the mountain," further integrating human use and natural context (Sahin 2009, 192). Coupled with the stone and natural light, the warm water completes the elemental cycle, such that Therme Vals may be seen as embodying an almost classical view of nature even as it forgoes any kind of classical architectural details.

Even the entrance to the baths gives the visitor the impression of entering some kind of ancient, elemental place, because "the main entrance is located at the back of the hotel complex at the cellar level," as if the structure was built specifically to accommodate this preexisting passageway (Reuber 2002, 25). The first passageway into the baths is made of black concrete, followed by a corridor where "water drips from simple copper spigots on one side, staining both the granite wall and floor with blood-red iron and bile-yellow sulfur," ending in "a cobalt-blue sandblasted glass door" (Reuber 2002, 25). This is the first introduction of color into the otherwise gray and black palate of the building, and once again it serves to exemplify the simplicity of phenomenological practice. Zumthor's design uses these three primary colors as a means of distinguishing between the different pools and baths in the complex, thus allowing each area to take on its own distinctive character while nonetheless maintaining a feeling of continuity.

Thus, the first thing the visitor sees after passing through the changing room is "the large rectangular bathing hall lit by 16 blue skylights overhead," which branches off into "a small contemplative cave lit eerily from below" as well as "a sunken red-hot grotto, where sulfurous water is imbibed from brass cups chained to a small circular brass railing" (Reuber 2002, 25). The different baths serve to highlight different features and connotations of a cave, with some areas highlighting a kind of natural serenity exemplified by the light filtering in to the open cavern, and others playfully enacting an almost hellish aesthetic so that the bath may be recognized as "a playful and joyful thing" (Spier 2001, 22). This "joke" is quite intentional, because the baths are meant to be a place of enjoyment and reflection, experiences not possible in an oppressive environment.

Instilling a sense of playfulness into the design is crucial if it desires to enact a phenomenological practice of architecture, because if it the building was domineering or otherwise restrictive then it would preclude the kind of individual experience that is so central to phenomenology. Surprise is a key element of this playfulness, because the design must simultaneously serve to comfort and relax the visitor (it is a spa, after all) while nonetheless confronting the individual's assumptions in order to generate a novel experience. The various branching caverns and grottoes serve this purpose, because depending on where one is, "occupants are able to comprehend the whole at certain moments and be surprised...

This embodies the phenomenological focus on the individual experience of a place, because the building serves as a kind of suggestive structure, offering just enough guidance so as to help visitors toward the production of a unique experience that nonetheless arises out of the formal characteristics of the architecture.
Even the auditory characteristics of the interior serve to highlight the individual sensory experience of the place, because although "the bath starts to sound terrible when there are more than a 100, 120 people in it and the children start to yell and scream," the size of the interior itself limits this possibility as much as possible so that the visitor can, in Zumthor's words "hear all the sounds […] hear the space" (Spier 2001, 22). This is crucial because the building itself serves to suggest its ideal use, so while it does not dictate the visitor's experience in any kind of rigid way, "the building can tell you better what it wants" such that one may achieve an ideal experience in a natural, emergent process. In a way, the building itself attempts to subtly recede from the visitor's mind, so that the experience has less to do with the solid, immovable structure and more with the ephemeral meaning-creation which occurs within the structure, thus "forc[ing] the distinction between one's formal understanding of the building through drawings, say, and one's experience of it" (Spier 2001, 23).

A perfect example of the "structured freedom" granted to the individual is the "elevated calming room" above the central bath area (Reuber 2002, 25). The room contains six lounge chairs for visitors to relax on, but the true genius of the room is not revealed unless the visitor is willing to actually relax and lay back, because "each chaise faces a small square window positioned at eye level when reclining to frame a personal vista of the valley beyond" (Reuber 2002, 25). While a visitor can of course have a view of the valley from the outdoor pool or patio area, the calming room once again includes small details which serve to celebrate the individual experience of the place by rewarding the visitor with a unique perspective should he or she be willing to engage in the activity (or inactivity) suggested by the chairs. Thus, as Zumthor himself describes, the room functions as a "sort of a background […] so that life comes in," reflecting the relatively simple structures and physical laws which help to produce the infinitely vast diversity seen in nature (Spier 2001, 24).

In this way, one may view the calming room as a microcosm of the phenomenological ideal, because it serves as a solid, central structure on which experience and meaning can grow like plants on a trellis, and this in turn represents one of the essential focuses of phenomenological practice, which is a consideration of the relationship between humanity and the natural world. Just as the entire building itself represents the blending of an intentional, subjective structure with the objective, emergent space of the mountainside and valley below, so too do the small windows in the calming room represent the interplay between structure and individual experience which gives meaning to the place. Without the individual reclining on the chair, looking out across the valley, the windows of the calming room are quite literally nothing; without the perception and consciousness of the visitor, they are simply empty space, no longer windows but rather mere holes.

Peter Zumthor's Therme Vals embodies many of the architectural ideals expressed in phenomenological theory by focusing on the individual possibility offered by a building which seeks to recognize and celebrate the unique attributes of a particular place. The baths are constructed from local granite which serves to integrate the building into the mountainside, but carefully positioned gaps allow light to filter through, thus relieving any of the oppressive weight that might otherwise arise in the visitor's mind by highlighting the crisp atmosphere of the higher elevation. Similarly, the natural spring water used throughout the structure provides a sense of slow change to the otherwise timelessness of the stone, simultaneously hinting at an age beyond human memory while providing a functional space for human use. Primary colors are sparsely used throughout the baths in order to differentiate…