A Watchtower on Fairy Isle.
The Watchtowers are magical towers that can be found all over Fairy Country, with the main one being located on Fairy Isle. They are large, stone towers, with a crystal top.
The towers allow fairies to spy on the human world, and can even be used to pull people and objects into Fairy Country. A lot of fairies are former humans who were abducted in this manner. However, as the need for new arrivals dwindled, the towers fell out of use and their workings have largely been forgotten by the time the series is set. Phinium and Lydia are among the few who still know how to use them.
A watchtower is activated by rotating a crystal at the top, after which the tower fills with a green fog in which one can see and hear the people or place that one wishes to see, but the image looks distorded. In the tie-in book "Hilda and the Fairy Village", this mist is referred to as "steam windows". The transmissions mostly work in only one direction. The people that are being spied on cannot see or hear the people in the watchtower, but they can notice a shadow cast by their observer and subconsciously pick up things being said by the observer.
Phinium and Lydia used their watchtower to keep an eye on Johanna after they were forced to abandon her, and also Hilda after her first encounter with a Fairy Mound. They used the tower to rescue Anders from a troll that was about to kill him. When Hilda saw her friends looking for Twig, she alerted Frida that Twig was inside Astrid's house. Victoria Van Gale also found a watchtower on the outer island she had ended up on after her botched Nowhere Space experiment. When Hilda finds her, Victoria has already made great progress with analyzing the towers workings. At the end of "Chapter 8: The Fairy Isle", she manages to use her tower to create a portal that takes her directly to the lair of The Fairy Entity.
