This the central Asian-style tomb of Abu Muzaffa Bahdur Khan, who reigned over Nakhchivan in the middle of the 18th Century. Only women are allowed in the inner-sanctuary. Behind the tomb are the remains of the walls of the citadel. The hills, where the walls sit, offer some beautiful views. Foreigners should be careful taking pictures from the area as it is likely to cause suspicions from the local police.
The area where many of the locals gather at night is at the Heydar Aliev Museum. Heydar Aliev was the first President of Azerbaijan after the fall of the Soviet Union. He was born in Nakhchivan. The museum is the center of the city is often the gathering place for many celebrations of holidays within the city. Unfortunately, I never had the opportunity to set foot inside of the museum, but I did meet many of the local while strolling through the area.
Directly across the street is the Nakhchivanian Drama Theater. There are occasional performances within. The inside is rustic but comfortable.
While mausoleum is the subject of many photos, there is a park surrounding it. The park is also where young lovers meet away from the watchful eyes of their parents. It is home to a carpet museum, a monument of Heydar Aliev, a tea house, relics from what is believed to be pagan rituals, and an Islamic mystic. The park offers some incredible views of sunsets over/behind Mount Ararat in Turkey and the Araz River which separates Nakhchivan from Iran. It is also a good place to just walk around.
If the weather is good, there is an older lady who operates a small museum in the lower section of the mausoleum. Even if you do not know Azerbaijani, Turkish or Russian, she will still talk to you as if you do. Donations are asked for.