Answer: It is dark and treacherous, while the courtyard is hot and sunny.
The excerpt provides details of both the Tomb, and the courtyard. We know that the Tomb is dark because when Hussain Khan emerges he is squinting his eyes. We also know that the Tomb is a scary place for the people outside, as they describe the sound of the grate as "awful" and terrifying." Finally, the text also tells us that the courtyard is hot and sunny because the sound echoed in the "heavy heat" of the courtyard.