1. Delhi is one of the 'greenest' cities in the world with a green cover of almost 20%.
2. The entire public transport of the city runs on environment friendly Compressed Natural Gas.
3. Qutub Minar in Delhi is the world's tallest brick minaret.
4. The walled city of Delhi originally had fourteen gates. Five are still standing. Here's the provenance behind their names. Ajmeri Gate: Facing Ajmer in Rajasthan; Lahori Gate: Facing Lahore in Pakistan. Kashmiri Gate: Pointing North to Kashmir. Delhi Gate: Road to earlier cities of Delhi Turkman Gate: Named after pious saint Hazrat Shah Turkam.
5. In between the rubble of the fifth city of delhi – Freoze shah Kotla stands the 3 century B.C. Ashokan Pillar. Emperor Feroz Shah Tughlaq brought this 27 tonne pillar to Delhi from Topar in Ambala, where the great Emperor Ashoka erected it.
6. Delhi has an International Toilet museum.
7. Khari Baoli is the Asia's largest wholesale spice market. A must visit for the once-in-a-lifetime overdose of a spice cocktail high.
8. Traffic in Delhi is like traffic in London. Drivers sit on the right side of the car.
9. Three-wheeled contraptions called Autos are a great way to see the city over short distances. And test your faith in God.
10. Delhi has not always been the capital of India. Under the British, Kolkotta had the honor for a long time till Delhi was reinstated in 1912.
11. Delhi has a rail museum with steam-age behemoths.
12. Every Delhite is ever ready to help you out with directions. They will direct you even when they do not know what you are talking about. So check, crosscheck. And check again.