Simplify the following text for a Grade 10 native English-speaking person.
Original: The castle is frequently known as HakurojÅ ( `` White Egret Castle '' ) or ShirasagijÅ ( `` White Heron Castle '' ) because of its brilliant white exterior and supposed resemblance to a bird taking flight .
Simplified: It is sometimes known as HakurojÅ or ShirasagijÅ ( `` White Heron Castle '' ) because of its brilliant white exterior .