This is a fantastic, hidden gem of India. Stepwells are large, flat wells that were once quite common in this part of India, and the Queen's Stepwell here is one of the largest and most ornate. It's surprisingly large in area: about 60x20 metres in area, and 27 metres deep. On the inside, every inch of the walls is covered in carving, mostly of Hindu gods but there are some secular figures in there as well. The carvings are extremely beautiful and in fantastic condition as well, as the site was completely silted over until its discovery in the 1980s. The surrounding area is well manicured as well, though there isn't anything to see at the site other than the stepwell, which unless you're super into photography, probably won't take longer than an hour to thoroughly inspect.
We accessed the site via a private car from Ahmedabad. It's about 2.5 hours each way, and we ended up paying about 3500 rupees to hire the driver for the day.
Overall this is a strongly recommended site. It's definitely a bit out of the way, but a trip that we definitely found worthwhile. It's a site unlike any other we've visited so far!