meaning for 昔日 xīrì:

  • - former days
  • - in the past

zhèxiē这些
yíjì遗迹
chōngfèn充分
zhèngmíng证明
cǐchù此处
xīrì昔日
de
hóngwěi宏伟

These ruins sufficiently attest the former grandeur of the place.