In several ways Ancient Nara is the opposite of the Kyoto WHS. While in Kyoto the temples and shrines are spread all over the entire city area and beyond, the most significant sites in much smaller Nara are located in a park on the edge of the modern city. Nara was the residence of the Japanese Emperor prior to Kyoto, and only for a relatively short time. This may be the reason why the diversity of sites and styles is smaller compared to Kyoto, but that doesn't mean that Nara is also less impressive.
Most travelers visit Nara on a day trip from Kyoto. However, I scheduled two full days for Nara and Hōryū-ji, which enabled me to visit all locations of these two WHS.

If you enter the core zone at Sarusawa pond, you first reach Konfuku-ji. In the 8th century, the temple consisted of more than 150 buildings, of which only a few have survived. Most striking is the five-story pagoda. It was completely destroyed several times in civil wars, the current building dates from the 15th century - reconstructions can also be historical, especially in Japan.
The must-see in Nara is Todai-ji and its large Buddha statue. Todai-ji is always described in superlatives: largest bronze Buddha statue, largest wooden building in the world. And indeed, everything seems to be at least one size larger than at other temples, not only the Buddha, but also the gates, the guardian statues etc. Over the centuries, Todai-ji (like many temples in Japan) was destroyed by earthquakes and fire, more than once (no surprise, it is made of wood). Even the Buddha has lost his head several times, the current one dates from 1692. However, the fact that it is a reconstruction does not diminish the pleasure of the visit. And another plus: it is allowed to take pictures of the Great Buddha.
The journey is more important than the destination, you might think when walking to the Kasuga-Taisha Shrine. The path through an old forest is lined with the incredible number of 3000 stone lanterns. The shrine is amazing as well. Actually, it was my favorite site in Nara. I liked the colours: the vermilion columns, the white walls, the green wood, and the blue sky above. The shrine is famous for its brass and bronze lanterns, that hang by the hundreds on all buildings and along the colonnades (photo). There is even a "dark room" to give an idea of ​​what it looks like when all the lanterns are lit. This happens only twice a year at special festivals. Entrance to the outer compounds is free, it opens early in the morning, but I would strongly recommend paying the 500 Yen fee to visit also the inner grounds.
Right behind to Kasuga-Taisha is the Kasugayama Primeval Forest. You can hike through the inscribed area on an 11 km loop passing Jizo statues and small temples and shrines. It took me about 2 hours. I wouldn't say it's a must-do, but it was a nice walk through an ancient forest, mostly cedars and maples, quite relaxing after days of crowded temple sites.
The Gangō-ji is considered the oldest Buddhist temple in Japan. That could be the reason for its inscription. Originally founded in Asuka, the temple was later moved to Nara. However, from a visitor point of view, it is significantly behind the other locations.

The next day after visiting Hōryū-ji, I went to the two temples in Nishinokyo District, west of Nara. I took the bus from JR Nara station and arrived 15 minutes later at the bus stop in front of the main gate of Yakushi-ji. The temple has a symetrical layout with the huge main hall in the center flanked by two pagodas. The eastern pagoda was still under scaffolding when I visited, but the works should be finished in 2020. Yakushi-ji was a nice surprise. I liked to explore the details of the colourful designed buildings, again vermilion columns, white walls and green doors.
Tōshōdai-ji is only a short walk away and has a completely different atmosphere and style. The buildings are lower and have a more simple and plain design compared to Yakushi-ji. Everything is surrounded by trees and lush foliage plants. I liked most the moss garden in the northeast corner of the complex.
And finally, the Heijō-kyō: it was more my tendency towards completeness rather than true enthusiasm that made me visit also the last part of the WHS. There is hardly anything visible left of the former palace, it is a huge and almost empty archaeological area. There are only a few recent reconstructions: the Suzuka Gate in the south, the Daigokuden (former Audience Hall) and the East Palace Gardens. Certainly, the least rewarding of all locations.

Visiting the temples in the Nara Park is certainly enough to tick-off the Nara WHS. But if you have more time, I would recommend to stay overnight and visit also the temples in the west of Nara.