Throughout history, religious architecture has aimed to inspire reflection and reverence through its forms, often drawing from the natural world to evoke the divine. Indonesian architectural practice RAD+ar, known for its ability to dissolve the boundaries between natural and built environments, have adopted this tradition across their latest project, the Sanctuary Tunnel Garden in a rural district near Bogor, Indonesia. The structure serves as a sacred retreat and an architectural exploration of light, space and spirit. By merging openness and intimacy, the chapel invites visitors to reconnect with the essence of faith and the untouched landscape.

The architecture of discovery

The chapel’s design redefines the archetype of religious spaces through bold simplicity. Its spatial composition begins with an inverted tunnel, an ambiguous void carved within the terrain that creates an interplay of light and shadow. This structure bridges the wellness retreat and the chapel itself, forming an organic dialogue between the built space and the extensive surrounding nature. The architecture seeks not just to house prayer but to echo it, crafting a physical journey through its geometric precision and material honesty.

Drawing inspiration from archaic exoskeleton constructs, the design emphasises structural repetition, juxtaposing robust forms with fluid, ramping circulation. This approach integrates the terraced terrain and leads visitors through the dense woods surrounding the site. The interplay of these minimalist structures with the organic environment creates a sensory experience, a discovery that unfolds slowly as visitors navigate the space.

Despite its imposing design, it maintains a modest footprint, covering less than 10 per cent of the estate’s area. This ensures that the surrounding natural terrain remains largely undisturbed. Shrouded in mist and interspersed with existing giant trees, the building merges with its environment, blurring the boundaries between architecture and landscape. Its undulating forms are separated from the all-glass walls, providing panoramic views. This transparency fosters a connection between the interior and the outdoors, enabling a harmonious blend of illumination, scale and texture. Natural radiance plays a central role in evoking a spiritual response. As the sun shifts, the interplay of light and shadow within the space creates a living, dramatic environment. This phenomenon evokes spiritual growth, a journey marked by moments of illumination and obscurity where understanding is constantly evolving.

The programme consists of three primary elements: the semi-public chapel, the Mother Mary spiritual garden, a private retreat villa and the guest villa. Each space carries its architectural language while remaining interconnected by a shared sense of fluidity. Within the chapel, flowing geometries carve out varying levels of familiarity, enhanced by dramatic natural light. This emphasises subtle transitions rather than abrupt separations, guiding everyone through spaces that feel at once personal and universal.

On the ground floor, it connects seamlessly to bodies of water on both ends, including a manmade waterfall and free-form terraces. These water features, combined with the surrounding woods, root the design firmly in its natural context. The chapel’s sacred core, a suspended space illuminated by light at the tunnel’s end, becomes the architectural climax. It is both landscape and structure, a gesture to the open-air gatherings of the past while embracing the formal rigour of modernist design.

A Sacred Journey

At the entrance, a bronze statue of Mother Mary greets visitors, symbolising a protective presence and setting the tone for the experiences that follow. Time feels suspended within the space’s spiritual journey. Visitors find themselves disconnected from the outside world’s relentless pace, immersing fully in the present moment.

The tunnel, a metaphorical passage, mirrors the spiritual path that challenges visitors to relinquish distractions and embrace openness. Its light-filled expanse creates an atmosphere of serenity and contemplation, guiding individuals toward an inner truth. The play of light and shadow here mirrors the spiritual journey itself: a movement from ambiguity to clarity, from seeking to understanding.

The semi-public chapel, with no reliance on ornate decoration, channels divinity through light, texture and silence. Visitors experience a heightened connection to the divine as they stand beneath the suspended sacred core of the chapel. This floating space, illuminated by light at the end of the tunnel, embodies the essence of spirituality: a moment where the earthly and the divine intersect.

The spiritual garden offers a continuation of this journey outdoors. Its winding paths encourage meditative walks, fostering a deeper connection to nature as an integral element of spiritual practice. The gentle sound of water from nearby terraces and the sight of towering trees create an environment that amplifies the feeling of harmony and interconnectedness.

For visitors at the villa, spirituality is woven into the daily rhythm. The villa is designed not merely as a place of rest but as a haven for prayer and reflection. Guests are enveloped in stillness and reverence, with expansive views of the surrounding landscape serving as a reminder of the vastness and beauty of creation.

What sets this project apart is its ability to balance the sacred with the profane. The 360-degree transparency of the chapel and villa blurs the line between inside and outside, between human-made and natural. This openness fosters a sense of humility and accessibility, breaking down the barriers often associated with sacred spaces. It allows the divine to be experienced not as something distant or unattainable but as an intimate, personal journey.

Some places don’t ask to be understood; they simply exist to hold what words cannot. The religious architecture project is akin to that; it is less a destination and more an invitation to linger in the unspoken, to rest in the subtle weight of what it means to simply exist.

Project Details

Name: Sanctuary Tunnel Garden
Office Name: RAD+ar
Firm Location: Bali & Jakarta
Completion Year: 2025
Gross Built Area (m2/ ft2): 650 m2
Project Location: Cigombong, Indonesia
Program / Use / Building Function: Chapel, Spiritual Retreat Villa, Religious Space
Lead Architects: Partogi Pandiangan, Antonius Richard Rusli