There are few natural offerings as serenely replenishing as a dip in a hot spring on a cold day. Primitively soothing and therapeutic, it’s no wonder that many cultures across the world and through the centuries have taken to them in one form or another. Japan, Iceland, Russia, Mexico, Ethiopia—all these countries and more boast a long history of humans basking in geothermal pools.

Hot springs—simple pools of water, in rock or sand, heated by the natural movements of the earth—remain irresistible, for both pleasure and health, especially when the temperature drops. Here are some of the best springs around the world to dip into.

JAPAN

The Japanese are extremely fond of their onsens, the local term for hot-spring saunas. An onsen tour would be incomplete without a visit to Hokkaido, a mountainous island in the far north, where storied springs are visited by cold macaques in the wintertime—the only monkeys in the world to partake in such pampering. On Hokkaido, check out the fall foliage at Jozankei Hot Springs. Note that swimwear is disallowed in most onsens.

In Gunma, a charming town full of hot springs on Honshu island, there is Takaragawa, a charming onsen nestled beside a picturesque brook in the mountains and once a popular haunt for shoguns and samurai.

COLORADO

Though hot springs abound across the American West, few states offer as many pristinely beautiful ones as Colorado. At the entirely natural, spring-fed Strawberry Park Hot Springs in Steamboat Springs, the legendary ski town, there is a no-light policy. Bask, then, in their 104-degree mineral water, within large natural-stone pools surrounded by pines, under a sprawl of clear stars. A small hike through the woods is required. But to really feel off the map, journey to Dunton Hot Springs in Dolores. Its six pools shine red from a skin-pleasing mineral cocktail found in the water, at more than 8,000 feet elevation.

NEW MEXICO

Often overlooked, New Mexico also has plenty of hot springs to relax in. Outside the artsy mountain town of Santa Fe, check out San Antonio Hot Springs, about two hours west. Accessible by either a burly vehicle or a five-mile hike, it boasts a series of pools carved along a hillside in the stunning San Diego Canyon. In the southern half of the state is the charming Jordan Hot Springs, located in the Gila National Forest. These little pools in the woods are not far from the Gila Cliff Dwellings, a collection of stone dwellings constructed by ancient nomadic tribes.

ICELAND

Like Japan, Iceland—another highly geothermal, geologically complex country—boasts a world-class hot-springs culture.

Make time for the Blue Lagoon, near Grindavík, a much-visited but spectacular bright sky-blue pool in the middle of coal-black lava fields (it also features a restaurant and a swim-up bar, along with its own skin-care line). For something more low-key, try the Secret Lagoon in Fludir, a lesser-known spot that features an active geyser. The springs at Landmannalaugar (say that five times fast), located inside Fjallabak Nature Reserve, in the southern Highlands, is another popular spring, offering breathtaking views of psychedelic mountains.

CHILE

Another geothermal mountainous country, Chile abounds with springs. At the remote Termas de Banos Colina springs, at the foot of the San Jose volcano near the Argentine border outside Baños Morales, are several pools overlooking snow-capped peaks. At such a chilly height, the steaming water will be much appreciated.

Then, like something out of a fantasy novel, is Termas Geometricas, a Japanese-inspired hot-spring resort located within a fantastically lush canyon rainforest in Villarrica National Park, dense with fog. Cherry-red walkways suspended over a stream lead to 17 pools, each with its own changing hut. Termas Laguna Verde, located near the highest active volcano on earth, Ojos del Salado, is rustic but unforgettable.