I would build a really, really big and awe-inspiring temple and plant a sacred grove around it. (I actually have the designs already, I made them years ago in case I suddenly obtain infinite resources.)
For this purpose I would first buy the land where a city stands, and possibly, if the city has surrounding small towns and villages, those too (it would be a really big grove so that when one is in the middle no lights, sounds or anything from the human civilization can reach, and the sky can FINALLY be black at night), raze it to the ground and start anew. I hate cities, and this would be the way I would do the most good (that is, create the most beauty), both with the destruction and the construction.
If you got a time-machine, but it would only have enough handwavium to work once (thus, no travelling back home), would you still use it? Where would you go?