Lowell is one, but there are more including the Kitt Peak National Observatory.
One synonym for astronomical observatories is "space observatories."
Yes, there are many observatories all around Europe.
I take that you are asking 'astronomical observatories'. 'Observatory' is a noun, observatories is the plural form. Astronomical is simple a modifier (adjective, in this case.)
Siegfried Marx has written: 'Sternwarten der Welt' -- subject(s): Astronomical observatories 'Observatories of the world' -- subject(s): Astronomical observatories
Alt-azimuth is the mount ussually found in professional observatories.
There are thousands of observatories in the world, ranging from small amateur setups to large professional facilities. The exact number can vary as new observatories are built and existing ones are decommissioned.
yes
mountains
observatories
Roger Hutchins has written: 'British university observatories, 1772-1939' -- subject(s): Astronomical observatories, History
Observatories need for the area to have dark skies so that they have a better view of the heavens. In Arizona, the City of Tucson regulates lights of businesses and streets so that the skies are dark enough for the astronomers at Kitt Peak.
No, atmosphere will block some spectrum.