A great planet that is not just Earth-like, but which is Earth, though in another universe. While Terra is much like Earth in many aspects--its appearance, its people, its animals--it is not quite an exact match. Its planetary system may appear familiar: a bright sun, an unusually large moon orbiting the planet, the other planets with which the pleasant green-and-blue planet shares its system, that's where the similarities end. Because while the planet and its planetary system may be just like ours, the galaxy beyond it is not: Terra's galaxy is not like the Milky Way in the least.
Terra's grand beauty is much like Earth, being what it is. The planet is made mostly of deep blue oceans, seas, and other bodies with water, with large continents breaking up the great expanse. The land is covered in green forests, jagged mountains, rolling hills and stretching plains, the beauty of nature precariously balanced with humanity's continuous growth. In more modern times, some of the pressure has finally been taken off of the planet, with its native humans having settled other planetary objects in the solar system, and even beyond it. Especial care is taken, these days, to preserve Terra and its nature: the origin not just of humanity, but of many of the galaxy's sapient people, humanoids and even those more distant.
Terra is in a somewhat unusual situation, simultaneously a popular touristic location and carefully guarded to ensure its continued existence and safety. As this planet is the origin of all humanoid species, and even of several other sapients, many find an interest in observing it, in seeing the (literally) distant root of their people. But humans have looked the end of their world in the eye and barely avoided it, and have in its wake become obsessed with its safekeeping. Most of the tourists allowed near Terra are not tourists at all, but scientists: people who have come to research this point of origin. Where they go and what they see is thus highly dependent on what they research: geology, biology, chemistry? Would it aid them more to look at Terra's deep oceans, its massive mountains, its bubbling volcanoes? Or at the history of humanity, as far as it can be traced back? Potentially even before the divergence of the galaxy's humanoids? Or do they need to look back even further, to animals who roamed Terra before humans ever graced its surface?