A system for improving visualization of at least a catheter in an organ of a patient, the organ comprising a heart, the system comprising: an output device ; and a processor , which is configured to: display, on the output device , a map of the organ and at least a first visual marker (66A-66C) overlaid on the map; receive a position, falling within the map, of a distal end of the catheter ; and display on the map (i) the distal end of the catheter in accordance with the received position, and (ii) instead of the first visual marker (66A-66C), at least a second visual marker (77A-77C, 88A-88C), which increases visibility of at least one of the map and the distal end , relative to the first visual marker (66A-66C), wherein the processor is configured to display the second visual marker (77A-77C, 88A-88C) instead of the first visual marker (66A-66C), in response to identifying that the position of the distal end is within a predefined vicinity of the first visual marker (66A-66C), wherein the processor is configured to produce the second visual marker (77A-77C, 88A-88C) by modifying at least one attribute of the first visual marker (66A-66C), wherein the at least one attribute comprises at least one of dimension, shape, opacity or position, and wherein the first and second visual markers are indicative of one or more parameters of ablation applied to tissue of the heart. an output device ; and a processor , which is configured to: display, on the output device , a map of the organ and at least a first visual marker (66A-66C) overlaid on the map; receive a position, falling within the map, of a distal end of the catheter ; and display on the map (i) the distal end of the catheter in accordance with the received position, and (ii) instead of the first visual marker (66A-66C), at least a second visual marker (77A-77C, 88A-88C), which increases visibility of at least one of the map and the distal end , relative to the first visual marker (66A-66C), wherein the processor is configured to display the second visual marker (77A-77C, 88A-88C) instead of the first visual marker (66A-66C), in response to identifying that the position of the distal end is within a predefined vicinity of the first visual marker (66A-66C), wherein the processor is configured to produce the second visual marker (77A-77C, 88A-88C) by modifying at least one attribute of the first visual marker (66A-66C), wherein the at least one attribute comprises at least one of dimension, shape, opacity or position, and wherein the first and second visual markers are indicative of one or more parameters of ablation applied to tissue of the heart. display, on the output device , a map of the organ and at least a first visual marker (66A-66C) overlaid on the map; receive a position, falling within the map, of a distal end of the catheter ; and display on the map (i) the distal end of the catheter in accordance with the received position, and (ii) instead of the first visual marker (66A-66C), at least a second visual marker (77A-77C, 88A-88C), which increases visibility of at least one of the map and the distal end , relative to the first visual marker (66A-66C), wherein the processor is configured to display the second visual marker (77A-77C, 88A-88C) instead of the first visual marker (66A-66C), in response to identifying that the position of the distal end is within a predefined vicinity of the first visual marker (66A-66C), wherein the processor is configured to produce the second visual marker (77A-77C, 88A-88C) by modifying at least one attribute of the first visual marker (66A-66C), wherein the at least one attribute comprises at least one of dimension, shape, opacity or position, and wherein the first and second visual markers are indicative of one or more parameters of ablation applied to tissue of the heart. <EOS>