Machan. A tree standing in the well of a double-height room, with tables against a wall of glass looking into the treetops. Open all day, and where the staff eat too.
Captain's Cellar. A vaulted brick cellar under the building, with oak casks for tables. The capital's only serious wine room, and small enough that booking the whole of it for 6 people is reasonable.
The Jiva Spa. Indian therapies, and nobody here uses the word wellness — an abhyanga with 2 therapists working in time, and a steam room that is actually hot. Ask for a late slot; the floor empties after 8.
The garden pool. A long rectangle in the garden, the tower over one side and old trees on the other 3. Heated through the Delhi winter, which is when you would come anyway.
Taj Club. A floor, a lounge and a butler rather than a lounge alone. Club rooms come with airport transfers, a check-in taken sitting down, breakfast in the lounge, and evening canapés substantial enough to count as dinner.