mangroves exist in Costa Rica 's Pacific saltwater swamps, forming a complex community with marine animals
and plants.

The rain forests of the Pacific, like Corcovado National Park on the Osa
Peninsula , are some of the most complex ecological systems on the planet. They maintain similar species to those found
in the Atlantic rain forests, and because of a short dry season, they also shelter some species common to dry forests.For Part II, click here.

This is the first of two articles that will explore Lacan’s idea that human subjectivity has the structure of a topological space.

In the early eighteenth century the city of Königsberg, now part of modern-day Russia, was connected by seven bridges which linked the two islands of the city with each other and the mainland.

The citizens of Königsberg had posed themselves the following problem: was there a way to walk through the city by crossing each bridge fully once and only once?

In 1735 a young Swiss mathematician, Leonhard Euler, decided to have a go.

His idea was that the map of Königsberg could be stripped of all its geographical attributes and isolated to just a few key features: the land masses which made up the city