Russian Fort Elizabeth built
1816 CE.
Shown on the map at 21.952°, -159.664°.
Pāʻulaʻula State Historical Park is a National Historic Landmark just southeast of present-day Waimea on the island of Kauaʻi in Hawaiʻi. It is the last remaining Native Hawaiian fort on the Hawaiian Islands, built in the early 19th century by natives with an Italian-based design provided by a German traveler who arrived on a Russian-American Company ship, as a project of High Chief Kaumualiʻi. The star fort was employed by the Kingdom of Hawaii in the 19th century under the name Fort Hipo (Hawaiian: Pāʻulaʻula o Hipo).
Text from the Wikipedia article Russian Fort Elizabeth, licensed CC BY-SA 4.0.