It became the Stratosphere.
Vegas World opened in July 1979 with 90 hotel rooms and a 15,000-square-foot casino. The sole owner throughout its 16-year existence was Bob Stupak, the self-proclaimed "Polish Maverick." When it closed in February 1995 to make way for the tower, Vegas World had grown to 1,000 rooms and an 85,000-square-foot casino.
Vegas World is gone but not forgotten. Millions of Vegasphiles recall the infamous VIP Vacation Package, one of the longest-lived and most successful -- though widely misunderstood and controversial -- gambling-based promotions in Las Vegas history. Stupak also introduced crapless craps and double exposure blackjack.
Stupak began the Stratosphere project in 1995, but ran out of money. He sold a piece of the tower to Lyle Berman, a Minnesota businessman and poker player, and eventually lost control of his dream. When building costs escalated and more money had to be raised through corporate bonds and a stock offering, Berman also got into financial trouble. And, when Stratosphere opened, revenues didn’t keep pace with operating expenses and debt service. Ultimately, Carl Icahn, a distressed-property investor almost without peer, wound up with the building for dimes on the dollar.
The only physical section of Vegas World that remains is the north half of the Stratosphere parking garage (you can tell by taking the old elevator down to the casino).
The whole wild tale of Bob Stupak, Vegas World, and the Stratosphere is told in the book No Limit – The Rise and Fall of Bob Stupak and the Stratosphere Tower by John L. Smith.