There are many changes between SimCity 3000 and its immediate predecessor SimCity 2000. These changes span both the integral city management aspects of the game, as well as its graphical and landscape aspects. More and newer city services are featured. These changes create a greatly different experience from that of SimCity 2000. The most notable change is the addition of the concept of waste management. In SimCity 3000, garbage begins to accumulate when the city grows to a medium size, and must be disposed of at the expense of the city. Farms and agricultural structures are also introduced, appearing on large light industrial zones in a city with low land value and little pollution. A new zoning density was also added, totaling three densities, compared to SimCity 2000's two. Business deals were another new concept to SimCity 3000; by allowing certain structures, such as a maximum security prison, to be built within the city, the player can receive a substantial amount of funds from them. Business deal structures, however, tend to have negative effects on the city, such as reduced land value. There are several changes to the graphical interface in SimCity 3000. Although the game retains the pseudo-isometric dimetric perspective of its predecessor, the actual landscape became more complex and colorful. In SimCity and SimCity 2000, the playable landscape is mostly brown, while in SimCity 3000, the playable landscape is a more realistic green color, along with other colors that progressively change by height, from beige (beach sand) to green to brown (bare ground) to white (snow). In SimCity 2000, land could either be flat or sloped, and all slopes were of the same steepness. In SimCity 3000, there are five distinct steepness of slope, creating more varied landscapes. There are different types of trees which can appear on the playable map, ranging from small, deciduous trees to towering redwoods. In addition to their limited life span, power plants and other utility buildings were also made vulnerable to decreasing maximum output due to age. All power plants have a life span, and additionally, the water facilities now have a life span as well. Although the concept of neighbor cities was introduced in SimCity 2000, it was greatly expanded upon in SimCity 3000. New for players is interaction with neighbouring cities, negotiating rudimentary business deals with other mayors, such as the sale or purchase of water, electricity or waste management services. These generate a monthly charge which is either added to or deducted from the player's treasury, in accordance with the deal. Canceling a neighbor deal would incur a penalty, unless the deal was cancelled when the other city wished to renegotiate. Although not strictly a city management aspect, SimCity 3000 simulates the effect of land value on construction much more realistically than in SimCity 2000. In SimCity 3000, land value creates very distinct neighborhoods which tend to contain na