Village well. I turned on my system monitor and returned to a well. Elsewhere in the game, I can just alt-tab between the game and the monitor normally. If I alt-tab out of the well screen, my system rapidly (many, many times a second) flashes between the monitor and the game until I alt-tab back to the game.
The framerate reported in the upper left corner of the game is typically 60 fps. It dips to 48 when on the well screen.