There are plenty of other markers and memorials scattered throughout the town, too numerous to list. The maps on the bridge over the train tracks list them with their relevant commanders.
岐阜関ケ原古戦場記念館, Gifu Sekigahara Kosenjō Kinenkan
This new museum (built 2020) offers a good introduction to the battle itself. It is especially helpful because the first two exhibits (both visual media - a bird's eye view of the battle and an anime-like 4D theater movie depicting what it was like in the fray) provide the necessary background to understand how the 6-hour battle went and why Tokugawa won. The upper floors contain mainly replicas (although some original artifacts and documents are displayed) of writings relating to the battle or Tokugawa's rise to power, and then goes in depth of the aftermath of the battle and the consolidation of his rule. Kids and the young at heart will enjoy the third floor, which offers a hands-on exhibit where you can play around with different types of weapons used during the battle (such as katanas, matchlock rifles, and battle fans). The fifth floor is an observation deck that gives a panorama of the battlefield and town, and has signs (in Japanese) that indicate where each important thing is/was. The staff don't speak English and about 85% of the exhibits have English translations, but the movies have English subtitles.
国指定史跡 関ヶ原古戦場 開戦地
A marker dedicated to where the first shots of the battle were fired. It also has benches and information boards that detail the order of battle and positions.
Higashi and Nishi Kubizuka
On opposite sides of the train tracks, two shrines commemorate the sites where two large mounds of the severed heads of fallen soldiers were buried. As per traditional Japanese concepts of reverence for the dead, these shrines are dedicated to all who fell in the battle, not solely forces of one side.
床几場 Shōgiba
Also called "Tokugawa's Final Encampment", this is the spot where Tokugawa Ieyasu held a council meeting after the end of the battle and was presented with the decapitated heads of the enemy's leaders. A small shrine marks the spot.
奥平貞治の墓
A leader who fought under the traitor Kobayakawa. He died while attacking Otani Yoshitsugu's army. The grave was built here by one of his descendants.
笹尾山 Sasao yama
To the north of the town on a small hill that offers a commanding view of both the town and the battlefield. This is where Ishida Mitsunari, Tokugawa Ieyasu's main opponent and leader of the Western Alliance at the battle, based his camp. Two rows of wooden palisades flank the base of the hill, and a stairpath allows visitors to walk up to the memorial at the top. Can easily be seen from the observation deck of the Gifu Sekigahara Battlefield Memorial Museum, as well as from most of the town.