Josune Bereziartu was born on January 19, 1972, in Lazkao, a Basque town of the province of Gipuzkoa, northern Spain.

[2][3] In 1998, Bereziartu came to international attention with her repeat of Honky Tonky at Oñati, which made her the first-ever female in history to climb an 8c (5.14b) route.

[2] In 2000, Bereziartu set a new record by becoming the first-ever female in history to climb 8c+ (5.14c) when she redpointed Honky Tonk Mix at Oñati.

[2][4] In October 2002, she set another record by becoming the world's first-ever female climber to climb a 9a (5.14d) route, when she redpointed Fred Nicole's Bain de Sang [fr] in St Loup, Switzerland.

In 2000, she made the first-ever female onsight of an 8a+ (5.13c) route in history when she climbed Bon Vintage at Terradets in Catalonia, Spain.

In 2002, she became the first-ever female to complete an 8B+ (V14) boulder traverse, when she solved La traversia De Balzola, at Baltzola in the Basque Country.

[9] Talking about her choices in a 2021 Climbing interview, she said: "Looking at my career with the perspective of age, I’ve learned that it’s important to maintain your freedom and to follow the things that excite you—not what others expect you to do".

With these redpoints, and with her first female 8b+ onsight completed in 2006, Bereziartu reduced the gender gap on multiple occasions, inspiring thousands of other climbers.