Begin with a pickup from your hotel in Reykjavik and travel by climate-controlled minibus to the Golden Circle, a 186-mile (300-km) scenic loop that circles the countryside around the capital.
Stop first at the UNESCO World Heritage–listed Thingvellir National Park, notable as the site of the world’s longest-running parliament and the point where the tectonic plates of Europe and North America meet.
Stretch your legs with a stroll, then drive to Lake Thingvallavatn. Head to the snorkel center, where you’ll get changed and pick up your equipment. Then, following a safety briefing, enter the crystalline waters with the guide.
Drift between the two continents and marvel at the neon-green seaweed and other underwater sights. The fissure’s visibility is renowned, and you can even see down to the lava fields, some 328 feet (100 meters) below.
Back on dry land, warm up with hot chocolate and sit down to lunch (own expense). Then, depart for Haukadalur, a geothermal valley studded with geysers and hot springs. Make a photo stop at Geysir, one of the area’s most famous highlights, before stopping at nearby Gulfoss.
Your tour then concludes with a drop-off at your hotel.