a fly in amber

Something from or indicative of a bygone era that still exists in the present in the same or similar form (like an ancient insect preserved in amber). Amongst the booming modernity of the city's glass-paned skyscrapers and hip, trendy restaurants lies a fly in amber—Madame Couture's Curiosity Shop, still in the exact same building as when it opened in 1874. My brother still lives at home with our parents, with no job, no girlfriend, and no motivation in life, still living as a child, like a fly in amber. It doesn't look like they've updated the school's computer lab at all in the last 30 years. It's like a fly in amber, right down to the dot matrix printers and Macintosh IIs.

a fly in amber

a curious relic of the past, preserved into the present.

The image is of the fossilized bodies of insects which are often found preserved in amber.