A new memorial opened on Tuesday in the Czech Republic on the site of a former Nazi concentration camp for Roma, after a communist-era pig farm was removed. “It’s very positive news for me that the whole project was completed,” said Jana Horvathova, the director of the Museum of Romani Culture, whose organization is in charge of the memorial. Roma and human rights activists had long demanded the removal of the farm from Lety, 60 miles (95 kilometers) south of Prague, where some 1,300 Czech Roma were sent between August 1942 and August 1943 during the Nazi occupation of what was then Czechoslovakia in World War II.