The currency used in Costa Rica is the Costa Rican colón (plural: colones), abbreviated as CRC. However, US dollars are widely accepted in many tourist areas, hotels, and restaurants. It is advisable to carry some local currency for smaller establishments and rural areas where US dollars may not be readily accepted. Credit cards are also accepted in most places, but it's always good to have cash on hand for situations where cards are not accepted or ATMs are not available.