Our Delhi siteseeing started with a trip to a mosque. A part of Delhi has a high percentage of Muslims and the mosque can accommodate 25,000 people at a time. There are a number of sets (35 or so) up to the entrance where all of the women in a our group had to don robes. Any men wearing shorts are also required to wrap robes around their bottom halves.
Photos inside are allowed only if you pay a $5 fee to do so (which I did not do). It is not ornate, has a feel and architecture of mosques I saw in Morocco.