What does the Apple Command key symbol (⌘) mean on Icelandic road signs?

Question

I've just returned from a holiday in Iceland (I can heartily recommend it, BTW). I took a break from Stack Exchange as well, but I guess one can never stop being a moderator... I couldn't help but notice the Apple Command key symbol, the logo of our sister site Ask Different

being used on a couple of road signs, e.g. this one near the Háifoss waterfall:

The Ask Different logo is derived from the Command key – we can't use an Apple-like logo since we're "not affiliated with or endorsed by Apple Inc. in any way." (see our footer).

Sometimes, a modified version with a caret ('roof') is used:

I thought I found the answer on an information board just inside Hveragerði which says it's for Hot Spring Areas:

but that doesn't make sense; the Háifoss is 'just' a waterfall and the Ráðhús is a town hall.

Bonus question: is this something Iceland specific or is it used in other countries as well?

Answer 1

I found the definitive answer when I was typing this question; while inserting the ⌘ in the question's title and hovering over it, the dialog showed me it's a Place of Interest Sign:

According to Wikipedia, it's called a Looped Square and it's mainly used for this specific purpose in the Scandinavian countries:

It is also known as the place of interest sign when used on information signs, a practice which started in Finland in the 1950s, spreading to the other Nordic countries in the 1960s.

To my defense, before Iceland I've only been to Helsinki as a tourist. (But maybe I should've checked the Wikipedia page about the Command Key first.)