Just a couple of kilometers away from Mitad del Mundo are the ruins of the Pucará de Rumicucho. This ancient Incan hilltop fortress was situated high on a hill, with sweeping views overlooking the valleys below. Mountains and volcanoes tower above it, giving it a dramatic location at the center of the Earth, right on the Equator. The name means "Fortress of Stone" in Kichwa, and it is believed that the Inca ruler Tupac Yupanqui ordered its construction between 1480 and 1500. Archaeologists have conducted digs around the site and confirmed that it was an important spiritual and astronomical center for the pre-Incan Caranquis, Quitus, Panzaleos, and Cuasmal.

Each year on the Summer and Winter Solstices, the Inti Raymi festivals take place here, when people come up here to spend the night and the following day. They adorn the ruins with flowers and fruit as offerings to the sun, performing dances throughout the night. Scientists come here on the Summer Solstice as well, verifying with GPS devices that on that day, the Pucará de Rumicucho sits exactly at latitude 0° 0' 0".