Wear Comfy, Non-Slip Shoes – Some areas underground are uneven, dusty, or a little slick—good footing makes a big difference.

Book Your Tickets in Advance – Tours often sell out, especially on weekends and in summer. Reserve ahead online to guarantee your spot!

Bring a Mask – The underground can smell musty and damp due to the humidity. Some visitors appreciate having a mask handy if they're sensitive to strong, earthy odors.

Allow Extra Time to Explore Aboveground – After the tour, wander Pioneer Square’s historic streets: bookstores, galleries, quirky cafés, and independent shops. It's one of Seattle’s most atmospheric neighborhoods.

Listen for the Weird Stories – Beyond the fire and rebuild, the underground tour is full of bizarre history: opium dens, gambling halls, brothels, and businesses that operated secretly after the city "moved up."

Pro Tip: If you're a big history buff, pair the underground tour with a visit to the Klondike Gold Rush National Historical Park museum nearby—small but fascinating and free!