A sacrifice cave is sacrificed to the public interest in cave visits, in the hope to keep people busy and protect all other caves this way.
This has nothing to do with sacrifices inside a cave, the cave itself is sacrificed, which is actually a rather turgid way of putting it. If you visit caves that have been visited for centuries, you will find many remnants of previous visitors, that is graffiti, rubbish and chipped speleothems. By the middle of the 20th century, cave explorers had had enough and started closing off well-visited caves on a large scale with iron grids. This has two obvious disadvantages, it costs a lot of money and labour, and the more criminal cave hyenas get a kick out of cracking them. There are a few other problems, most notably the problem that cavers are also locked out and have to find out which caving club has the key first. And the other is that it gives cavers a bad reputation, an air of secret society, which is exactly the opposite of what they do.
The counter reaction was the establishment of sacrificial caves, i.e. caves that are conveniently located, easy to reach, reasonably interesting and not dangerous. These were then even promoted a little, signs were put up and a board with a cave map and background information was placed at the entrance. The tourism office was allowed to include them in their brochures. Suitable objects were above all those which contained no archaeological sediments and hardly any dripstones. These were then often the caves that had been freely accessible for many years anyway. Sometimes dangerous places were also made secure or closed, or made safer with a permanently installed ladder.
The sad result of this strategy, however, became obvious after only a few decades: these caves were sacrificed to destruction and vandalism completely unnecessarily. Vandalism increased continuously, but knowledge about caves or cave protection did not. And so, in the 1990s, voices arose that fundamentally rejected the concept of sacrificial caves. They concluded that people who go into caves and are allowed to break off stalactites only learn one thing, namely that it is okay to take stalactites as souvenirs. Instead of teaching people vandalism, cavers started teaching awareness and responsibility. Sacrificial caves have been replaced by offers of cave trekking tours, where participants receive a safety briefing, learn the necessary techniques, but also basic geological knowledge and, above all, the idea of nature conservation. American speleologists summarised the concept in three concise rules 50 years ago:
The task of the caving guides is now to explain these three rules in detail.