El Diablo Restaurant in Islote de Hilario is a unique building that would not have been constructed had it not been because of its creators. The architect was Eduardo Cáceres, but it was designed by artist César Manrique, who was always drawn to challenging environments.

This mound was a plot of land characterised for the almost superficial heat coming from underneath it. From the first attempts to reconstruct the area, workers agreed that it was impossible to erect a building with traditional solutions because not even the most solid of foundations could support the constant heat from the bowels of the volcano.

It was then when Jesús Soto, working with Manrique, suggested the creation of a subfloor that would ease the high temperatures. They decided to create a series of layers alternating concrete, clay soil and rocks that would be placed under the building. This would condition the heat, and would channel it towards what today is the furnace of the restaurant.

Almost by coincidence, after checking the behaviour of the water that workers used to refrigerate the machines, Jesús Soto came up with the idea of using this phenomena by placing the current metallic tubes that allow geysers to form.