Sakaiminato is a small town with a long history as a port -- in fact, sakai means "border" and minato means "port" in Japanese. A feudal lord built moated Matsue Castle on nearby Mount Katsuyama in 1611, and one of the country's most important and ancient Shinto shrines, National Treasure Izumo Grand Shrine, is about 90 minutes away.
You'll see lots of fishing boats here, since it's Japan's third busiest fishing port, with 683 tons of fish caught in 2017. There's a lively fish market during tuna season, which is from June to November, and winter is snow crab season. (A favorite local dish is kanisuki nabe, a crab hot pot made with vegetables, tofu, mushrooms and a special soy sauce.)
If you're a manga (graphic novel) fan, you may recognize the name Shigeru Mizuki, a favorite local son, who has a museum and street dedicated to him. You'll find it lined with bronze sculptures of his yokai (spirit monster) characters and shops selling manga-related items.