Feroz Shah Tughlaq established Ferozabad
  well and distantly established. According to him the population of the city
  at that time was around 1,50,000. As compared to the earlier sites of
  substantial settlement in Delhi which had been further south only - Lal
  Kot/Qila Rai Pithora (now the area around the Qutub Minar), Siri a little to
  its north-east, and Tughlaqabad in the hills to the south-east, Ferozabad
  was much further north than these three early settlements. It was also the
  first of the capitals to be built on the bank of the river Yamuna.
       Feroz Shah Kotla was the grand and opulent royal citadel of the city.
  Visitors, invaders like Timur and contemporary chroniclers have given
  glowing descriptions of its buildings. Unfortunately most of its priceless
  stones and gilded and painted features have become extinct today. Later
  on, materials for the construction of cities like Din Panah and Shergarh in
  the south and Shahjahanabad in the north were plundered from here.
       The walls of the citadel are as high as 15 metres high and have a slight
  slope on the outside. The top parapets have now disappeared but the arrow
  slits can still be seen. Historians have listed many structures in the fortress.
  One of them, "The Palace of the Wooden Gallery/Overhang" was for the
  officers of the emperor, and the "Central Quadrangle" or the "Palace of the
  Public Court", was where the emperor held court for the general public.
       It is a three-storey building which was specially commissioned by
  Feroz Shah to support the Ashoka pillar. This pillar was set up at Topra,
  near Ambala, by Emperor Ashoka. The pillar had several edicts regarding
  Ashoka"s Dhamma inscribed on it. This monolith pillar is 13 metres high,
  with a diameter of 65 centimetres at the top and 97 centimetres at the
  bottom. Feroz Shah brought it to Delhi and reinstalled in the fort. The
  building, now in ruins, originally had a railing and eight domed chhatris
  (pillared kiosks) at the top, and a stone lion at each corner.
Lodhis The Lodhis further developed the tradition of combining many of
the new devices brought by the Turks with indigenous forms. Both the arch
and the beam are used in their buildings. Balconies, kiosks and caves of the
Rajasthani-Gujarati style are used. Another device used by the Lodhis was
placing their buildings, especially tombs, on a high platform, thus giving the
building a feeling of size as well as a better skyline. Some of the tombs are
placed in the midst of gardens.