1.Santa Cruz de Islote, Colombia: The most densely populated island
Santa Cruz de Islote is an artificial island located off the Colombian coast. Although it is only two times the size of a soccer field, around 1000 people call it home. This highly populated island lacks all modern comfort, including sewage. However, locals use solar panels to generate electricity. With a high sense of community, there is no need for policemen as there is no crime. Just like Venice, this island is expected to sink, so you should start packing your bags!