Tuesday The Hellenic World venue of the Foundation of Greater Hellenism continues its exhibition on digital approaches to urban architecture, running until May 22. At 254 Pireos, Building 6. Thursday Kotzia and Syntagma squares and the National Gardens take on the colors of spring as the City of Athens hosts a series of flower shows, flower arrangement displays and presentations on botany and history, among other events, from Thursday to May 22. Also in Kotzia Square, the plant nurseries’ cooperative of Acharnes, Attica, is organizing a special display and will give advice on creating organic gardens in urban environments, such as on balconies and rooftops, until May 18. Friday The Federation of Thessaly Industrialists hosts a conference toward facilitating local business penetration foreign markets, at the Larissa Imperial Hotel at 7.30 p.m. Deputy Foreign Minister Evripidis Stylianidis will give the keynote address. Sunday The Fourth International Yachting Symposium opens at the marina of the island of Poros and runs to May 12, promoting yachting tourism in Greece. For information, tel 210.452.6335.