If you live in Delhi and if you have visitors from other towns visiting you then you would have probably been there few times like me??.
Red fort was built by Shahjahan and is similar to red fort in Agra. There are three small museums in Redfort. One of the museum is dedicated to Independence struggle of India and one has old weapons used by the britishers. This fort was also used by Britishers as an army cantonment so you can see mutiple colonial buildings inside the fort.
The last museum has stuff related to mughal dynasty. While you enter the fort from Lahore gate you go through one of the oldest covered bazaar of India. A visit to red fort will take you to a journey of past and is worth a visit.