Back in 2014, Nathan Barnhart created a weekly feature called ‘Tough Travels’, which he hosted over on Fantasy Review Barn. Inspired by The Tough Guide to Fantasyland by Diana Wynne Jones – a tongue-in-cheek parody of the fantasy genre – it would spotlight a different trope every week, and invite other bloggers to compile their own lists of examples. Despite being put to rest eighty-three (83!) weeks later, ‘Tough Travels’ was widely successful, with over fifty blogs participating at one time or another. On April 1, 2017, Fantasy-Faction received Nathan’s permission to revive Tough Travels once more…

This week the topic is strongholds:

The Tough Guide offers information on various kinds of fantasy strongholds. For example, you might be looking for CASTLES, complete with ‘frowning battlements, slit windows and multiple defensible spiral stairways inside’ and which ‘occasionally adorn the heights for pictorial effect’. Or perhaps TOWERS, which ‘stand alone in WASTE AREAS and almost always belong to wizards.’ Towers are often ‘several storeys high, round, doorless, virtually windowless, and composed of smooth blocks of masonry that make them very hard to climb. The Rule is that there is also a strong no-entry SPELL, often backed up by a guardian DEMON.’

Strongholds are indeed a staple of both sf and fantasy. Here a few my favorites:

Asgard
The home of the Norse deities and heroes in myths and Marvel universe.

Olympus mountain
The home of the Greek deities.

Camelot
The castle of King Arthur and Queen Guinevere.

Sherwood forest
The home of Robin Hood and his Merry Men.

The invisible, multi-dimensional Library by Genevieve Cogman
Only very specific people can get inside the Library and from very specific doors.

City and Castle of Amber by Roger Zelazny
Amber is the home for the royal family of Amber and it sits in one of the two real worlds. All other worlds are just reflections of the two true cities.

Lothlórien by J. R. R. Tolkien
The well-guarded forest which is the home of elves and their rulers Lady Galadriel and Lord Celeborn.

Menzoberranzan by R. A. Salvatore
One of the most forbidden, and exciting for some adventurers, is the underground dark elven city of Menzoberranzan where the first good dark elf Drizzt Do’Urden was born. He also managed to escape the clutches of his evil matriarch mother, Malice.

From comics:
Baxter Building from Marvel
The Fantastic Four have had a couple of other bases but the most familiar to me is the Baxter Building. Even though they had tenant living on the lower floors, the upper floors were heavily secured against intruders.

The Watchtower from DC
Justice League’s Moon base might seem impenetrable at first glance, especially that on, you know, the Moon. Or in some stories a floating space station.

Blue Mountain by Wendy and Ricard Pini
The ancient glider elves lived in the Blue Mountain for thousands of years until the Wolfriders came to unite them with the other elves. It’s a whole mountain and the elves live in caves near the peak.