The Kremlin is standing firm over the annexation, though the United States and the EU on Monday again condemned the takeover of Crimea, portrayed the referendum as a sham and said sanctions would remain in place. Even some Western diplomats, however, say there is little chance Russia will hand Crimea back to Ukraine.
"Crimea is a region of the Russian Federation and of course the subject of our regions is not up for discussion," Kremlin spokesman Dmitry Peskov said on Tuesday.
Many Russians say Crimea's annexation rights a historical wrong by Soviet leader Nikita Khrushchev who gave the territory to Ukraine in 1954, long before the Soviet Union collapsed.
Russia has underlined its commitment to Crimea by announcing a military build-up on the peninsula, home to Russia's Black Sea fleet and to more than 2 million people, of whom around 60 percent are ethnic Russians. It has also promised to pour in money to boost the local economy and help residents.
Some pensioners say they now receive much bigger pensions and are happy with the support from Russia.
"Life has changed for the better. Pensions and salaries got bigger, roads are being repaired, and in general the government started working," said one who gave his name only as Alexander.
Businessmen, however, complain of growing obstacles.
"In Ukraine, everything was simple," said 41-year-old Emil Mustafaev, a real estate developer from Sevastopol. "Now everything is closed to us."
He said he could no longer buy building materials he needs from Ukraine, which has severed all rail connections to the peninsula, while only Russian airlines now fly to Ukraine.
Many supplies from Ukraine have been disrupted: Farmers lack water to irrigate crops, residents face frequent power outages and it is proving hard to attract tourists to Crimea's beaches.
The Crimean government said tourist numbers more than halved in 2014, down from 6 million visitors the year before.
Moscow has promised to establish alternative routes and has awarded a $3 billion contract to Arkady Rotenberg, a Putin ally, to build a bridge across the Kerch Strait that would connect Crimea to the Russian mainland.
Referring to the bridge, a tour operator who gave his name only as Ivan said: "Without the bridge there will be no boom."