Words in Vietnamese and other languages written on Hanoi’s Cot Co Flag Tower. The flag tower is a popular landmark in the city. Hoa Phong Tower in Hoan Kiem Lake area suffers the same situation. Visitors even carve words on the site. Writing on Pen Tower A bamboo brush near Pen Tower has been tainted with lines of words Those found defacing monuments face fines of between VND1-3 million. Many historical sites in Hanoi have been spoilt by graffiti.