Both nations claim Santa Rosa de Yavarí, a tiny island of just 3,000 people that sits in the Amazon River, more than a thousand miles from their capitals.

Peru maintains it owns Santa Rosa Island based on treaties about a century old, but Colombia disputes that ownership because the island had not yet emerged from the river at the time.

Santa Rosa is one of those newer islands. The land now contains forest and farmland, as well as the village of Santa Rosa de Yavari.

The island is made up mostly of forest, farmland and a small village known as Santa Rosa de Yavari, which has a population of less than 1,000 people, according to Peru’s latest census.

The island is made up mostly of forest, farmland and a small village known as Santa Rosa de Yavari, which has a population of less than 1,000 people, according to Peru’s latest census. Santa Rosa was ...

Peru maintains it owns Santa Rosa Island based on treaties about a century old, but Colombia disputes that ownership because the island had not yet emerged from the river at the time.

The island is made up mostly of forest, farmland and a small village known as Santa Rosa de Yavari, which has a population of less than 1,000 people, according to Peru’s latest census.