The Grandparents and Grandchlidrens walk is approximately 4km, with start and finish line at Cais Português, near the Expo at Rossio dos Olivais, Parque das Nações. This walk is open to all who wish to participate. Signup is FREE. Souvenirs for all. Sign up during SportExpo, at the Parque das Nações, Pavilhão de Portugal, on October 12 and 13, from 10am to 8pm.