Fig. 1 – Canopy Tower penetrates the rain forest canopy on Semaphore Hill.

Before being transformed into a premier birding destination, the Canopy Tower was a United States military radar tower. Built in 1963 following the Cuban Missile Crisis, it was used primarily for defense of the Panama Canal, a vital U.S. controlled economic and military thoroughfare, from potential Soviet attack (fig. 2) (refs. 1 and 2).

Fig. 2 – International shipping routes.

Fig. 3 – Panamanian General Omar Torrijos and U.S. President Jimmy Carter sign the 1977 Panama Canal Treaty beginning the process of handing the Canal Zone back to Panama .

Fig. 4 – Operation Just Cause, the 1989 U.S. invasion of Panama. Source: Frank Martin/U.S. Military Academy)

Fig. 5 – Prolonged drought has impacted the water supply to the locks linking the Atlantic and Pacific Oceans. In 2023, to address this crisis, the Panama Canal Authority began restricting the number of ships allowed passage.

Fig. 6 – The rainforests of the watershed straddling either side of the Panama Canal, harbor a diversity of plants and animals and help reduce erosion and sedimentation to the canal.

Fig. 7 – Keel-billed Toucan in the Soberania National Forest.

In September of 1988, with the Cold War on the wane, the radar tower was activated as Site One in the Caribbean Basin Radar Network and used by the U.S. government to detect airplanes suspected of transporting illegal drugs from South America (source: History of the Canopy Tower/


The radar tower and surrounding Semaphore Hill – 35 hectares of rainforest within the 35,000 hectare Soberania National Park – were transferred in November 1996, from the U.S. to Panama according to the terms of the Torrijos-Carter Treaties (Figs. 3, 5, 6 and 7).

Fig. 8 – Transformation of the radar tower into a birding lodge.

Fig. 9 – The military geodesic dome, now painted yellow, penetrates the rainforest canopy of the Soberania National Forest.

Fig. 10 – Roof deck for birding.

In 1997, the government of Panama signed a long-term contract with Raúl Arias de Para to transform the tower into a center for rainforest observation and ecotourism in Panama.


‘…my project did not entail building inside a national park, something that is taboo to park authorities. Rather it meant transforming an old military installation into a center for the observation and study of the rainforest. To complete my project I did not have to cut down a single tree or use bulldozers or heavy machinery. I was simply proposing to remodel an existing military building and make it suitable for visitors interested in observing the rainforest and its inhabitants.’  Raúl Arias de Para

Fig. 11 – The decommissioned radar tower with concrete fuel tank housing in the foreground.

After Canopy Tower was inaugurated in 1999, Raúl Arias de Para asked us to incorporate the adjacent concrete piers that previously held military fuel tanks, into a pavilion for rainwater harvesting.

Fig. 12 – Pavilion deck elevated on concrete housing with tensile roof for rainwater collection.

Fig. 13 – Ramped access to the shaded deck with tensile canopy above.

Fig. 14 – Pavilion with swimming hole charged by rainwater.


Soberania National Forest, Panama




1,500 sqf


Adaptive reuse of U.S. military fuel tank armature


Wood deck, steel frame, tensile fabric membrane


Raúl Arias de Para


Lindy Roy with Anthony Burke


Okavango Delta Spa, Alaska Rendezvous Lodge, Tehama Street Incubator, Cancer Alley, Noah’s



Ref. 1 - US controlled 10-mile wide Panama Canal Zone 1924.

Ref. 2 - Cristobal in the US military controlled Panama Canal Zone.