When visiting another country, like UAE, it's very important to consider the culture, religion, practices and rituals. Even more important is respecting those beliefs, even if they may differ from your own.
There are many activities in Abu Dhabi. deciding which ones to do, where to go and how to get there, is a little tricky. Your best bet, is getting a 48 hour Big Bus ticket. Technically the tour begins at Marina Mall with 16 stops and can be finished in a day. There's also a separate Yas Island route which would be ideal for day two. With the 48 hour ticket, you could probably finish the entire tour in that amount of time. But if you're limited for time, I would recommend: Observation Deck 300 in the Jumeirah at Etihad Towers With your Big Bus ticket it costs $10USD. The views are incredible from the 75th floor. It's the highest public viewing area in the city.