Purana Quila (Old Fort) that stretches over one and a half kilometres long and eighteen metres high may host only two ancient Monuments within its precincts but its exterior ramparts are also seen with two other ancient and beautifully architected monuments named Khairu'l Manzil which was earlier a Masjid (mosque) and later transformed into a Madrasa (Islamic Seminary) and the Sher Shah Gate or 'Lal Darwaza' which means 'Red Gateway' built on the southern exterior end of the Old Fort.
Behind Purana Quila is an ancient Temple of Lord Shiva called Bhairav Temple which dates back to the Pandavas era. Some say that this Temple was probably constructed by the five brothers over their first city 'Indraprastha' while they were living here. Excavations by the Archaeological Survey of India also revealed many relics and artefacts dating to that period which have been carefully preserved in the Museum within the Old Fort Complex.
Khairu'l Manzil Masjid Monument lies opposite Purana Quila on the western part of Mathura Road in South Delhi and easily accessible by local transport. It was constructed by Maham Anga in 1561. She was known as one of the most influential personalities during the reign of Mughal Emperor Akbar and in fact she was initially the foster mother or wet nurse of the Emperor who highly respected her and kept her in the same status as his own biological mother. Maham Anga was also the biological mother of Adham Khan who was a General in the Army of the Mughal Empire and a nobleman very close to the Emperor who considered him like his own brother. Adham Khan was killed and his Tomb lies in Mehrauli in South Delhi and constructed in the typical Lodhi style.
When Emperor Akbar was a child, Maham Anga had ruled over the Mughal Empire for a short while and was responsible for making all the important decisions relating to the goodwill and survival of the Mughal Kingdom. In fact when Akbar, though a minor then, was crowned the Emperor of the Mughal Empire and during his rule when he grew to an adult, he would often seek the advice of Maham Anga before making important decisions for his Empire. This Mosque was constructed with the help of a very powerful courtier and relative of Maham Anga named Shihab-ud-din Ahmad Khan.
The Khairu'l Mosque is considered as one of the most auspicious amongst the other palatial houses and made with a five arched opening that leads to a huge Prayer Hall covered with plaster. This Mosque homes an elaborate double storied gateway on its eastern end made of red sandstone which was later converted into a Madrasa (Islamic Seminary). The central hall of the mosque is covered with a Dome shaped roof while the surrounding sections are topped by vaults. These prayer chambers were earlier seen with elaborate decorative carvings and inlaid with enamelled tiles however today, only an inscription on the Central Hall is seen that reveals that this mosque was constructed by Maham Anga.
The Sher Shah Gate also known as 'Lal Darwaza' which means 'Red Gateway' lies towards the north of the Khairu'l Manzil Masjid built by Emperor Sher Shah Suri during the 16th Century AD. This gate formed the entrance and exit point of the sixth medieval city of Delhi built by Sher Shah Suri to accommodate his commoners under the Suri Dynasty. This Gate faces the city and the Old Fort and still lingers towards the western end of Purana Quila though it was built to provide an entry and exit point from the southern end of the medieval city. This gate was built with a very minimal usage of local quartzite and maximum use of very rich red coloured sandstone from where it derives its name. Adjacent to the Sher Shah gate, you will notice a series of chambers used as arcades which have verandas in the front and small openings where the local inhabitants of the sixth city could set up their respective shops.
These Monuments beside the Old Fort are open to public viewing on all days and requires no entry fee or photography charges as these structures are located in an open area on the side of the road which can be partially viewed from your vehicles too.