Simplify the following text for a Grade 9 native English-speaking person.
Original: There are old merchants ' mansions richly decorated with wood and stone carving in the historical center of Ulan-Ude , along the river banks which are exceptional examples of Russian classicism .
Simplified: There are old merchants ' mansions richly decorated with wood and stone carving in the historical center of Ulan-Ude , along the river banks . They represent beautiful examples of Russian classicism .