Past the yellow tape, carrying maps that lead the way to where the dungeon entrance is thought to be, they don't need to walk very far for the magical effects to start appearing. Elisabel, being a trained witch, is able to feel it earlier and more keenly than the other two, but any adventurer who's gone on more than a couple of dungeon raids can recognise the feeling of magic in the air. It feels... nice. Quite unlike anything else, of course, but people who have tried to describe the feeling relate it to stepping out into the late spring sun after spending a while in a cold house, or taking a deep breath after your nose was blocked for two weeks, or waking up refreshed without an alarm to a day off work. It's relaxing, and it feels a bit like you're more alive, like this is where you're meant to be, that you're getting into your element.
And the environment agrees. Even before they're magical, the plants and animals in the periphery of dungeon entrances are more alive, healthier, more energetic, their colours more vibrant, their smells crisper, even the sounds are clearer. In a new and presumably-small dungeon like this, it's not overwhelming, but many adventurers report not wanting to leave the vicinity of the more powerful dungeons because the rest of the world just feels kind of drab by comparison.
Then the magic starts. A single tulip, which should not exist here, grows almost as tall as the trees around it. A pair of green and golden bell frogs looking at each other, both as big as a poodle, occasionally chirping at each other and calmly ignoring the party. A little pond whose water glows faintly where a couple of fairies no bigger than thumbs that from a distance look like balls of golden light with butterfly wings. Things that didn't use to exist on Earth, five years ago, but which now do.