When you are at the Sabz Burj roundabout, there are several boards announcing many other things, except Humayun’s Tomb, at the lane entrance that leads to the World Heritage Site. 
A red board does appear,
but a little ahead, by the time when one has crossed the lane and will possibly have to either take a U-turn or drive back a little.
Although availability of authorised tourist guides is a problem, there is a site exhibition and a children’s book about the monument for sale. Apart from the absence of first-aid facilities, the parking area for the monument is very small.
