Pambamarca (alternate, Pimbamarca) is an eroded stratovolcano in the Central Cordillera of the northern Ecuadorian Andes in Pichincha Province. it is 25 miles (40 km) northeast of Quito. The summit is at an elevation of 4,062 metres (13,327 ft).

The mountains of the Pambamarca in the Andean Highlands of Ecuador has many Pre-Columbian fortresses that predate the arrival of the Spanish in the region; Pambamarca has the greatest concentration of these forts. The Pambamarca Fortress Complex has been studied with participation by many international organizations, universities, and the Government of Ecuador with the objective of exploring the cultural landscapes, its prehistoric, historic and contemporary cultures, particularly of Ecuador's important Pre-Columbian cultural heritage. In 1998, Pambamarca was placed on the tentative List of UNESCO World Heritage Sites.

The fortifications originated with the Inca Empire who conquered Ecuador easily, and established themselves at Quito. Noting that the local indigenous community settled in Pambamarca were docile, the Incas thought that they could move in and occupy the territories outside Quito. But they faced serious resistance, and the war lasted 17 years before the Incas could finally conquer the Ecuadorians in the 1500s, with the fall of the fortresses. Following this, the Incas built many fortresses and lived in them. Among the provinces to the north of Quito the pre-Hispanic fortresses are concentrated in the mountain range of Pambamarca.

Inferred from the Cayambe pottery in use in the region, archaeologist examining the area are of the opinion that Cayambe culture has prevailed "as some peoples decided after many years of resistance and warfare to simply lay down their arms or become allies with the Inca."

After Spanish people invaded Ecuador and Peru, not only smallpox took a big toll on the local population of Inca but due to the superior gunpowder power of the invaders their last stronghold at Vilcabamba also fell in 1572.

After the Spanish conquest of Ecuador the Spaniards built estates known as haciendas. The Cayambe were subjected to forced labour in these estates, working on wool processing and living in primitive homes.

According to a legend that relates to the period, Huayna Capac, ruler of the Incas with an ambitious plan of winning the Cayambe got muddled in a 17 years' war even though they invaded with a large army. The Cayambes noted the large army of invaders had retreated to a large and strong fortress. When the Incas laid siege on the fort, the Cayambes’ were not cowed but gave a brave fight which eventually forced the Incas to lift the siege as they had lost many men in the fight.

However, the Incas finally defeated the Cayambes and forced them to retreat to the shores of the lake Yawarkucha. It is also said that the Incas cut the throats of their enemies and threw them into the lake, which turned red with blood, and thus the lake got the epithet "Yawarkucha" meaning "blood lake". This aspect of the legend is to be confirmed by further explorations by archeologists examining the areas.