Pichincha volcano is the closest one to Quito. The nearest accessible point to the Rucu Pichincha is the top of the Teleférico de Quito, from there you can walk. The city of Quito is surrounded by several volcanoes. South-west of Quito, there is the Antisana Volcano, while to the north-west is the Cayambe volcano. If you are willing to travel a little more, going north there is the Imbabura volcano, Mojanda Lakes and Cuicocha caldera.
Going South, there are the Quilotoa caldera and the Cotopaxi volcano, both of them are great tourist destinations. Chimborazo volcano, Ecuador's highest volcano, is located near the city of Riobamba, in the province of Chimborazo.