Beijing is surrounded by four heavenly altars, or 迟á苍, and Ditan (Altar of the Earth), situated in the north within grounds that are today a public park, is one of them. A square open-air platform, the altar was where imperial rites were performed at summer solstice. Although not meriting a special trip, the park is a good place to see Beijingers at play, especially at the exercise area in the northeast corner.
Some 8km due south is Ditan's more famous sibling, the Altar of Heaven, otherwise known as the Temple of Heaven Park. To the east of the old city, in Ritan Park, is the Altar of the Sun, while to the west is the Altar of the Moon (Yuetan Park).
For the first few days of Chinese New Year, a huge, carnival-style temple fair is held at Ditan Park.
Ditan is also a good place to walk off a hearty dim sum feast at Jīn Dǐng Xuān, just outside the south gate.
