The Locus Amoenus is a literary device of a 'pleasant place' and is more prevalent in pre-modern literature. The locus amoenus is characterized by the presence of trees, grass, and water, and is the stereotypical nice place to spend time. It can be found in Tolkien's Shire and Lothlorien, as well as in the similar green and humble places scattered through genre fantasy. In Cliche, loci amoenus can be found on any of the sections of the map that are green (not dark lands, exotic lands, or the frozen lands)
The Locus Amoenus is a pristine place, untouched by man and unharmed by organized agriculture or the blade of progress. Should there be residents of locus, they are removed from civilization, and are 'noble savages' and are thus unencumbered by the negative attributes of progress and society. This is important as it places the locus as a strong and direct foil to the heavily developed and industrialized world that we live in.
The park is not a locus amoenus, though it might often have the key attributes: trees, grass, and water. The Park is not a pristine environment, with added walkways, lights, security cameras, monuments or artwork, and the ever present human element. There is going to be trash, or trash cans, and other people. The presence of other people can actually be the most disruptive aspect. Rather than a pristine reflective place, a park can be a meeting place for kids and teens, for sports and exercise enthusiasts, social events, and after hours, some parks play host to less savory activities such as gangs, drug deals, and other things that are the reason you don't go to the park after dark.
The Locus Amoenus is a retreat, a place for the character to find peace and a chance to find themselves. This can be as literally as a resting place to sleep and heal from injuries, to as metaphorical as escaping society to escape from it's demands. It can also be a place that is to be protected, akin to a sacred grove. The advancing forces of evil will destroy the locus amoenus without a second thought, spurring the characters to action, despite the fact that the locus generally has little magical, strategic, or tactical value.
In the Lord of the Rings, the Shire is unimportant. It cannot provide soldiers for the side of good, and destroying it would be little challenge to the forces of evil. It provided a pastoral home for the heroes, a place to care for a protect, when they had already seen the corruption in Gondor, and arrogance of men and elves, the folly of dwarves and their greed. There were no fortresses, no valuable mines, no major cities, no major trade routes, no key passes or river crossings, and the forces of good and evil weren't going to go to war over it.
The Unpleasant Place, characterized by evil or dead trees, stagnant and poisonous water, and brambles and other thorned plants instead of green grass. As an inversion of the locus amoenus, this place wears people down. It is unclean, unhealthy, and unpleasant. The creatures that live there are likewise loathsome and foul, biting insects and poisonous things. Resting here is to invite disaster. Such places are haunted by the dead, the misshappen trolls and ogres who dont care about the unpleasantness, and the foul creatures that can lurk under the surface of fetid water.
The Exotic Place, it shares many attributes with the amoenus but has a different purpose. The Exoticum demonstrates that the characters are not home, and are in a foreign place, surrounded for foreign things, so much that the infinitely familiar trees, grass, water trinity are themselves, foreign. Trees will be of a decidedly different nature, replacing the standard Amero-European deciduous trees with palm and other cycad like trees, or even venturing into magical exotic with glowing trees, or simply alien plant life. The same goes for the water, and the other ambient plantlike. For the residents of the exotic land, this is their locus amoenus, and a place with sycamore and oak trees and burbling creeks and fields of tall grass are going to be exotic.
An easy thing to forget with exotic locales is that for the residents, these locales are not exotic. For the people who go to and from the bazaar of wonders everyday, it is as exotic as going to the mall. Likewise for other locations, for the residents of the Forest of Dread and Evil, it's just where they live, and the outsiders, they bring their own problems into it.
The Locus Summae is a stark and barren place, of hardship and desperation. There are few is any trees, little or no water, and grass is a cool memory. Where the amoenus is a place of rest and reflection, the summae is a brutal challenge, to rest is to surrender and die. There are no residents, there is no shelter, there is only enduring the location until it is passed through. In a narrative use, the Summae is a crucible for the heroes, where their mettle is tested.
Mordor, Mount Doom, Hoth, roughly 75% of Westeros