Alto Relevo – Clube de Montanhismo is a nonprofit environmental and outdoor recreation association founded on 23 June 1998 and based in Valongo, Portugal. As an environmental non-governmental organisation, it combines adventure activities with the protection of nature, local heritage and historic sites. Its sections cover canyoning, mountain biking, climbing, caving, mountaineering, trekking, snowboarding and skiing, offering members opportunities to take part in activities and develop skills across a range of disciplines.

The club organises walks, mountain outings, public events and specialist training, including introductory caving courses recognised by the Portuguese Federation of Speleology. Some activities are open to the wider community, while others are reserved for members and may require registration, insurance or a participation fee. Alto Relevo also researches and promotes regional heritage, particularly Roman mining in Valongo, through conferences, publications, mapping and a documentary. Its website shares activity notices, event reports, caving surveys, climbing guides and information about the organisation.