Delhi is one of the greenest national capitals of the world, with its own reserve forests and lots of parks and gardens scattered across the city. While the majority are modern plantations, some have been around for centuries and are also home to some fabulous monuments. The best of the lot is by far the vast Lodhi Gardens, which has some of Delhi’s most splendid medieval tombs—some half a dozen emperors are buried here. The gardens also include the National Bonsai Garden, and are popular with joggers, morning walkers and picnicking families.
Other less fine medieval gardens include Shalimar Bagh and Qudsia Bagh, both dating back to Mughal times, and both with remains of Mughal pavilions and mosques. The Deer Park at Hauz Khas includes a number of interesting tombs and mosques, plus is adjacent to the imposing madarsa and tomb of the medieval Delhi Sultan Firuzshah Tughlaq—all with free entry.
If you’re in Delhi during the early spring, do check if the Mughal Gardens at the Rashtrapati Bhavan (the President’s estate) are open: they open for a month for the public, are free, and are a mass of really gorgeous flowers.