Muspelheim, also known as Muspell, is one of the Nine Realms of the World Tree and is the home of the Fire Giants. Muspelheim is known as "The Realm of Fire", stated to be the source of all heat in the Nine Realms. It is the home of Surtr the brave and his descendants, the Fire Giants, that are prophesied to burn down and destroy the God Realm of Asgard during Ragnarök. As their only purpose is to cause Ragnarök, Mimir noted that no Fire Giant will appear until it begins.
Muspelheim is described as a hot and glowing land of fire, home to the fire giants, and guarded by Surtr, with his flaming sword. It is featured in both the creation and destruction stories of Norse myth. According to the Prose Edda, a great time before the earth was made, Niflheim existed. Inside Niflheim was a well called Hvergelmir, from this well flowed numerous streams known as the Élivágar. Their names were Svol, Gunnthro, Form, Finbul, Thul, Slid and Hrid, Sylg and Ylg, Vid, Leipt and Gjoll. After a time these streams had traveled sufficiently far from their source in Niflheim, that the venom that flowed within them hardened and turned to ice. When this ice eventually settled, rain rose up from it, and froze into time. This ice then began to layer itself over the primordial void, Ginnungagap. This made the Northern portion of Ginungagap thick with ice, and storms began to form within. In the Southern region of Ginnungagap, however, glowing sparks were still flying out of Muspelheim. When the heat and sparks from Muspelheim met the ice, it began to melt. The sparks would go on to create the Sun, Moon, and stars, and the drops of melted ice would form the primeval being Ymir: "By the might of him who sent the heat, the drops quickened into life and took the likeness of a man, who got the name Ymir. But the Frost giants call him Aurgelmir." In the Prose Edda, Gylfaginning foretells that the sons of Muspell will break the Bifröst bridge as part of the events of Ragnarök: In the midst of this clash and din, the heavens are rent in twain, and the sons of Muspell come riding through the opening. Surtr rides first, and before him and after him, flames of burning fire. He has a very good sword, which shines brighter than the sun. As they ride over Bifröst it breaks to pieces, as has before been stated. The sons of Muspel direct their course to the plain which is called Vigrid. The sons of Muspel have there effulgent bands alone by themselves.
A land of primordial fire and blistering heat home to a tribe of slumbering fire giants, Muspelheim is an unending landscape of lava flows, volcanic ash clouds and noticeable signs of giant activity from ages past, though today it is completely lifeless. Its ruler Surtr, the original fire giant, has not been seen or heard from in millennia; he too is presumed to be slumbering deep within Muspelheim's fiery crust until the time of Ragnarok comes, whereupon Sutr and the other fire giants will rise again to lead all giants into battle against the Gods. His famous sword can be seen embedded in the peak of the realm's highest and most powerful volcano next to the slumbering Valkyrie of Fire Gondul, who was imprisoned there by the Valkyrie Queen Sigrun. The land of Muspelheim is home of the rare Fire Giants, of which were descendants of the original Titans who survived the Titan Wars and swore revenge. The Originals were more like the Frost Giants. Knowing of their weakness to sunlight, they used genetic hybridization to merge with some of the Sirian tribes they came upon in Africa, granting them newfound immunity to fire, heat and sunlight. Creating a new caste of Giants so to speak. As a result of their loss, their ruler Surtr plans on destroying the Asgardians during Ragnarok as previously stated. Like the other Giant tribe, they built domains beneath the Earth and in terms of Muspelheim, no human could survive the intense heat and temperatures of Muspelheim for any length of time. A place forsaken and forgotten by the Gods, knowing it's host holds no favor for them and has no issues destroying anyone that dare enter his domain. These beings still roam beneath the Earth and will not step foot above ground until Ragnarok comes. They will be part of the Titan Army that will once again declare war against the Gods / Annunaki, and will likely be destroyed. For them it's all or nothing, which is why many of their minions above ground are going for broke in trying to remove the humans from the planet before what is to come, because the odds of winning a war on two fronts becomes exponentially stacked against you. I do not know if any of the Draco factions are still allied with this faction of the Titans or not. Their MO is total destruction and burning everything in their path, and the only lineages that resemble this type of behavior are the Amelekites, and their love for burnt sacrfices, primarily the children of their enemies, but their homes and cities as well. If you ask me about the location of Muspelheim in modern day, it's an underground domain that's deep beneath the surface that is located in the area of northern Africa that extends northward towards Jötunheim westwards towards Niflheim. The vast array of tunnel networks that extends from the Middle East to Europe is what connected the cities and caverns or domains if you prefer of the various Titan lineages who survived the Titan Wars. They do not always get along due to the double cross of the original Titans during the Grigori Wars / Atlantean Wars and many of the networks were destroyed between rival factions as a result, but many of these tunnels and domains still exist to this day. It's why some places are off limits to humans and don't even appear on Google Maps. As many know, the major entrance to Agartha is indeed located in / above Antarctica.