Olivero Bland Studio, winners of the Public Medal at London Design Biennale 2018 , are back in London to speak about friendly boundaries that promote the public realm and create neighbourhoods. Their practice is based in Guatemala, in the 4 Grados Norte urban development, which is carefully designed and set to promote, create, socialize and cause human interaction. An ongoing and growing community of artists, chefs, filmmakers and designers make 4 Grados Norte a true urban oasis worth visiting. This is one example of how the ongoing creation and intervention of boundaries between the private and public space can be a detonator to urban change and the collective conscioussness the drives communities. This talk is a brief exploration of Case studies (proven and ongoing) of urban detonators in Guatemala and Central America that through design have been responsible for positive change.