Alternative schools are valuable because they explore non-conventional models which may contain the keys for a global educational change. The three alternative schools analysed for this research through ethnographic and biographic-narrative approaches emerged as an answer to failure and other injustices occurring in traditional schools (violence, exclusion, authoritarianism, cultural imperialism, unsustainability, etc.). This allows us to analyse how a model against the legitimation and perpetuation of these social and environmental injustices is constructed. The article will delve into how alternative schools lay the foundations for a more just world through self-knowledge, self-esteem and respect, questioning the effectiveness of traditional schools in terms of values, peace, respect, coexistence and participation. Results show us how to organise a school which recognises each person, allows participation, distributes resources equally and trains students who can detect injustices and mobilise against them.