Apparatus for decoding transform coefficient blocks encoded in a data stream, comprising: a decoder configured to extract, from the data stream, for a respective transform coefficient block, a significance map indicating positions of significant transform coefficients within the respective transform coefficient block by extracting, by context-adaptively entropy decoding, first-type syntax elements and second-type syntax elements, wherein each of the first-type syntax elements at least indicates, for a respective position within the respective transform coefficient block, whether a significant transform coefficient is present, and wherein each of the second-type syntax elements at least indicates, for a respective position within the respective transform coefficient block, whether a transform coefficient at the associated position is the last significant transform coefficient according to a scan order in the respective transform coefficient block, and the values of the significant transform coefficients within the respective transform coefficient block; and an associator configured to associate each of the first-type syntax elements and each of the second-type syntax elements to the respective positions of the respective transform coefficient block in the scan order, wherein the decoder is configured to use, in context-adaptively entropy decoding a current second-type syntax element, a context which is selected depending on a number of significant transform coefficients in a predetermined neighborhood of the current second-type syntax element. a decoder configured to extract, from the data stream, for a respective transform coefficient block, a significance map indicating positions of significant transform coefficients within the respective transform coefficient block by extracting, by context-adaptively entropy decoding, first-type syntax elements and second-type syntax elements, wherein each of the first-type syntax elements at least indicates, for a respective position within the respective transform coefficient block, whether a significant transform coefficient is present, and wherein each of the second-type syntax elements at least indicates, for a respective position within the respective transform coefficient block, whether a transform coefficient at the associated position is the last significant transform coefficient according to a scan order in the respective transform coefficient block, and the values of the significant transform coefficients within the respective transform coefficient block; and for a respective transform coefficient block, a significance map indicating positions of significant transform coefficients within the respective transform coefficient block by extracting, by context-adaptively entropy decoding, first-type syntax elements and second-type syntax elements, wherein each of the first-type syntax elements at least indicates, for a respective position within the respective transform coefficient block, whether a significant transform coefficient is present, and wherein each of the second-type syntax elements at least indicates, for a respective position within the respective transform coefficient block, whether a transform coefficient at the associated position is the last significant transform coefficient according to a scan order in the respective transform coefficient block, and the values of the significant transform coefficients within the respective transform coefficient block; and an associator configured to associate each of the first-type syntax elements and each of the second-type syntax elements to the respective positions of the respective transform coefficient block in the scan order, wherein the decoder is configured to use, in context-adaptively entropy decoding a current second-type syntax element, a context which is selected depending on a number of significant transform coefficients in a predetermined neighborhood of the current second-type syntax element.