One of the must-see FREE sites to visit in Abu Dhabi is the Sheikh Zayed Grand Mosque.
The Dear Wonderful Hubby and I took the public bus to the Mosque. We got a bit lost, looking for the public entrance (grins), but the security guards stationed around the Mosque’s beautiful grounds were extremely helpful. As was everyone we encountered.
Mosque rules apply. Shoulders and knees and, for female-facing people, heads must be covered.
I always travel with a head scarf in Muslim countries. I also cover my shoulders. And I never wear anything shorter than below-knee-length capris.
That is, IMHO, respectful outside the Mosque also. The women seem to appreciate my efforts (they are friendlier and more likely to offer help) and the men tend to show me more respect.
There was an awesome and FREE English-language tour, which gave us access to parts of the Mosque other visitors didn’t have and our guide shared with us the history and the architecture of the Mosque.
Take your time, if you can, at the Mosque. The details are exquisite and everywhere you look. It is very much a work of art. And, if you can find a quiet, uninhabited part of the Mosque, you will likely FEEL the spiritual vibes emitting from it. I found it to be an emotionally powerful place.