In the melting pot
Definition 1 of 2
Pro Tip 1/3Cultural Diversity
Refers to diverse groups coexisting and interacting within a society or space. 
The university campus is in the melting pot, with students from all over the world.
Pro Tip 2/3Positive Nuance
Often implies a beneficial coming together or harmonious diversity. 
The street food festival was in the melting pot of local culinary delights.
Pro Tip 3/3Not Literally
Used metaphorically, not about physical melting but a blend of diverse elements. 
The team's strategy was in the melting pot of innovation and experience.