NASA New Horizons space probe shows Pluto has ice mountains 11,000 feet tall

A spacecraft flew past Pluto at a distance of 7800 miles, and NASA released images captured by the Long Range Reconnaissance Imager Telescope Camera from as far as 476,000 miles away. The data suggests Pluto has 11,000-foot mountains made of water ice and may feature volcanoes and geysers.

What instrument was used to take images of Pluto?

What geological features are suggested to exist on Pluto?