Where the huge velarium that Nero had stretched across the Colosseum at Rome, that Titan sail of purple on which was represented the starry sky, and Apollo driving a chariot drawn by white, gilt-reined steeds?

尼禄横跨罗马斗兽场的幕，代表空的紫帆，阿波罗驾驶由镀金缰绳的白骏马牵引的战车在哪里？