Nothing remains of Tottori Castle, or more properly the ruins of Tottori Castle, but its stone foundations and original wooden gate. Its dates of construction and full history of use have also been lost to time, but it is most famous for the 200 day long 1581 siege that eventually forced the castle's starving Daimyo, Tsuneie Kikkawa, to surrender to Toyotomi Hideyoshi. The reason the siege lasted so long is because Tottori Castle made great use of the landscape for defense. A river forms part of the moat, and the rest of the castle is built into the side of Kumatsu Mountain. The San no Maru (3rd [outer] circle) wall rises right out of the mountain-side of the river moat, and between there and the Ni no Maru (2nd [middle] circle) there are multiple walls that elevated the structures they once supported as high as 90 or so meters above the surrounding area. The actual tenshukaku (the castle tower) was on the summit of Kumatsu Mountain, 263 meters above sea level. There are only 2 ways up to the Ni no Maru compound (and one of them appears to be a modern addition), and only 1 way, a long and steep climb, up to the Tenshukaku. The passing of centuries has left the tenshukaku’s stone foundation and its well in a less than proud condition, the hike to the summit is best made for the expansive view across all of Tottori City, the port of Tottori, the Sea of Japan and the sand dunes. Benches at the summit make a good place to have lunch.
Tottori Castle’s best structures are between the moat and the Ni no Maru. Sakura and pine trees, and a small shrine in the compound make Tottori Castle a pleasant place to take a stroll and a great place to view the sakura when they are in bloom. A 19th century, European-style mansion (Jinpukaku) where the Edo-era Ikeda Clan lived out its final days, and a junior high school are built within the moat on the grounds of the San no Maru. Both buildings detracted somewhat from my experience (I want my castles authentic, dangit) but the castle ruins are still a must see if you happen to be in Tottori.
Tottori Castle Ruins are free and open 24/7. They are a ¥150 bus ride away from Tottori Station on the blue or red loop lines or on many of the other buses running through out the city. Check the signs or ask at the information center inside Tottori Station. Happy Travels!