Haibane Renmei, Tenshi no Tamago Recommendations
Both have beautiful art and at times a similar feel. They are both set in heavily developed, atmospheric worlds.
They both use deep symbolism, like religious themes, beliefs and dogma. They are ambiguous and can varying interpretations.
Both anime have heavy doses of symbolism, religious imagery and a unique, dream-like atmosphere.
The setting in both anime appear to be based off of an old European city, and the location is largely abandoned in both (moreso in Angel's Egg than in Haibane Renmei).